# Difference between Detroit Diesel and EMD? **URL:** \ **Category:** Engineering\ **Created:** [May 22, 2020, 5:53pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522 "2020-05-22T17:53:47Z")\ **Posts on this page:** 17\ **Page:** 3
**Author:** ![SeaEagle](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/seaeagle/32/17788_2.png) [@SeaEagle](https://forum.gcaptain.com/u/SeaEagle)\ **Post date:** [May 30, 2020, 4:54am UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/41 "2020-05-30T04:54:44Z")
Although my pop never served on subs, he helped the missle program. Polaris and Posieden. Fire control dude. Did sea trials on some nukies as a civie after he retired.One thing that those guys that attended his retirement gave him his dolphins. How fucking cool was that. He was in tears. My soft spot was for sub guys ever since,nukie or diesel. ---
**Author:** ![jimrr](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/jimrr/32/38358_2.png) [@jimrr](https://forum.gcaptain.com/u/jimrr)\ **Post date:** [May 30, 2020, 4:44pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/42 "2020-05-30T16:44:40Z")
I haven’t hardly done anything with the newer 4 stroke EMD, am more familiar with detroit but from a engineering standpoint i’d probably want to deal with a more specific aspect of the particulars. ““in general”” … encompasses quite a bit of territory!! ---
**Author:** ![cmakin](https://avatars.discourse-cdn.com/v4/letter/c/48db29/32.png) [@cmakin](https://forum.gcaptain.com/u/cmakin)\ **Post date:** [June 1, 2020, 1:48pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/43 "2020-06-01T13:48:39Z")
Like anything else, I sailed with good and bad diesel sub engineers. . . . but all were great guys, even if they weren’t the best engineers. . . . .and yeah, would gladly bend an elbow. . .and then two days later bitch about what I found they did when I was home. . . . . ---
**Author:** ![beby](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@beby](https://forum.gcaptain.com/u/beby)\ **Post date:** [June 7, 2020, 12:25am UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/44 "2020-06-07T00:25:26Z")
One thing I have noticed, is you can push a lot more tonnage on the water than you can on land with the same size engine. ---
**Author:** ![Seadjon](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Seadjon](https://forum.gcaptain.com/u/Seadjon)\ **Post date:** [June 7, 2020, 3:07am UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/45 "2020-06-07T03:07:03Z")
Yes. ---
**Author:** ![rustbucket](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/rustbucket/32/16902_2.png) [@rustbucket](https://forum.gcaptain.com/u/rustbucket)\ **Post date:** [June 7, 2020, 4:26am UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/46 "2020-06-07T04:26:56Z")
Yeah, there aren’t any hills on the water ---
**Author:** ![Chief\_Seadog](https://avatars.discourse-cdn.com/v4/letter/c/67e7ee/32.png) [@Chief\_Seadog](https://forum.gcaptain.com/u/Chief_Seadog)\ **Post date:** [June 7, 2020, 3:34pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/47 "2020-06-07T15:34:07Z")
There might not be any hills on water but there are currents. In my youth I spent some time on the upper Mississippi on a towboat. We didn’t go very fast up river. ---
**Author:** ![SeaEagle](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/seaeagle/32/17788_2.png) [@SeaEagle](https://forum.gcaptain.com/u/SeaEagle)\ **Post date:** [June 7, 2020, 7:25pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/48 "2020-06-07T19:25:20Z")
But that ride downriver was a screamer. No brakes ---
**Author:** ![MarkG4040](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@MarkG4040](https://forum.gcaptain.com/u/MarkG4040)\ **Post date:** [December 17, 2023, 3:58pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/49 "2023-12-17T15:58:29Z")
Some of the gear boxes cant stand 900 with the 710s i just got off a triple screw full ahead was 850 with the falk boxes ---
**Author:** ![BargeMonkey](https://avatars.discourse-cdn.com/v4/letter/b/b5a626/32.png) [@BargeMonkey](https://forum.gcaptain.com/u/BargeMonkey)\ **Post date:** [December 17, 2023, 5:22pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/50 "2023-12-17T17:22:24Z")
Any of the conventional boats Im on with Rexroth heads they are cut back to 850ish. Filling in on another boat for a week a while ago, walking around downstairs and see this, light boat across the harbor 🤦‍♂️ went up and started chewing people the fuck out. ![20221031_001234](https://us1.discourse-cdn.com/flex016/uploads/gcaptain_maritime_forum/original/3X/5/c/5c29864edde29853bf9a1c4cf45d39c5ecb68f60.jpeg) ---
**Author:** ![NucNereus](https://avatars.discourse-cdn.com/v4/letter/n/278dde/32.png) [@NucNereus](https://forum.gcaptain.com/u/NucNereus)\ **Post date:** [April 7, 2025, 5:55pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/51 "2025-04-07T17:55:43Z")
My first look at a diesel was in the engine room of USS Nereus, a Fulton-class sub-tender. I recall that the ‘ultimate’ emergency shutdown method for a run-away engine was to stick the ‘horn’ of a Carbon-Dioxide fire extinguisher in the intake duct of the engine and… WHOOSH, which would shutdown the engine and also radically change the clearances in the roots blower. There were six engines in each engine room, two 12-278s for ships service and four 16-248s for main propulsion (one later converted to ships service), if I remember correctly. ---
**Author:** ![Steamer](https://avatars.discourse-cdn.com/v4/letter/s/3d9bf3/32.png) [@Steamer](https://forum.gcaptain.com/u/Steamer)\ **Post date:** [April 8, 2025, 10:16am UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/52 "2025-04-08T10:16:33Z")
> [@NucNereus](#): > > the ‘ultimate’ emergency shutdown method for a run-away engine was to stick the ‘horn’ of a Carbon-Dioxide fire extinguisher in the intake duct of the engine and… WHOOSH, which would shutdown the engine and also radically change the clearances in the roots blower. Reality check … One of the FMs on the our diesel sub suffered a slow motion runaway after an overhaul. The first attempt to stop it was to shut all the intake dampers, hoping to suffocate it. That didn’t work, it just collapsed all the sheet metal trunking. Next we tried the CO2 trick, that made little difference, just a bit of slowing. We used all the extinguishers on the boat but could not stop the engine. Finally the base fire department dispatched a CO2 tanker and we were able to flood the engine and stop it. If you have ever cooled a 6 pack of beer with a CO2 extinguisher you would know that a CO2 bottle is a long long ways away from removing enough BTUs from a roots blower to alter anything, much less dimensions. ---
**Author:** ![Cheng](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/cheng/32/57534_2.png) [@Cheng](https://forum.gcaptain.com/u/Cheng)\ **Post date:** [May 17, 2025, 3:47pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/53 "2025-05-17T15:47:57Z")
I worked for UPRR for a few years. Learned a lot about EMDs over that time. Albeit that our shops were set up with overhead cranes and the fact that we would have impacts and Tame wrenches (a calibrated hydraulic torques wrench on a cart) to remove and set the crab nuts, I could pull a power pack and have it on the deck in 20 minutes, clean and install it in an hour and a half by myself. We could condemn, pull and install a turbo and load test it on a saltbox in an eight hour shift. Just a tidbit for those guys who are still running EMDs with turbos. There are two ways to test your clutch. While running disengaged, throttle up by pulling the rack by hand to 850-900 RPM and just let it go. The engine will burp if the clutch is functioning. It doesn’t mean it isn’t worn but if it doesn’t burp, the clutch hasn’t retracted enough to go back on there gear. The best way to check to see if the clutch has failed is to pull one of the air filters, use a broomstick to turn the compressor fan. If the turbo turns both directions, the clutch has failed. Works 100% of the time. ---
**Author:** ![KPChief](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/kpchief/32/26_2.png) [@KPChief](https://forum.gcaptain.com/u/KPChief)\ **Post date:** [May 17, 2025, 4:37pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/54 "2025-05-17T16:37:16Z")
> [@Cheng](#): > > The best way to check to see if the clutch has failed is to pull one of the air filters, use a broomstick to turn the compressor fan. Here I thought it was if you did a magnet sweep in the sump at the drive end and came up with rollers. That’s a joke, I say that’s a joke son. ---
**Author:** ![Cheng](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.gcaptain.com/cheng/32/57534_2.png) [@Cheng](https://forum.gcaptain.com/u/Cheng)\ **Post date:** [May 20, 2025, 2:31pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/55 "2025-05-20T14:31:20Z")
> [@KPChief](#): > > > [@Cheng](#): > > > > The best way to check to see if the clutch has failed is to pull one of the air filters, use a broomstick to turn the compressor fan. > > Here I thought it was if you did a magnet sweep in the sump at the drive end and came up with rollers. That’s a joke, I say that’s a joke son It doesn’t have to come apart to lift and stay off the clutch. All it has to do is disengage and stay disengaged. If it does, it will turn in both directions. ---
**Author:** ![NucNereus](https://avatars.discourse-cdn.com/v4/letter/n/278dde/32.png) [@NucNereus](https://forum.gcaptain.com/u/NucNereus)\ **Post date:** [February 12, 2026, 5:26pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/56 "2026-02-12T17:26:53Z")
Fire-extinguishers worked pretty well on a Cleveland 248 engine. And something messed up that blower. ---
**Author:** ![DirtSailor](https://avatars.discourse-cdn.com/v4/letter/d/f1d935/32.png) [@DirtSailor](https://forum.gcaptain.com/u/DirtSailor)\ **Post date:** [February 15, 2026, 5:23pm UTC](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522/57 "2026-02-15T17:23:33Z")
> “Detroit diesels are two strokes, and they make an extremely distinct sound. Their main job is to turn diesel fuel directly into noise.” > > - Reddit [Previous page](https://forum.gcaptain.com/t/difference-between-detroit-diesel-and-emd/55522.md?page=2)